Iridescent surface



(No Modl.) v

J.JAC0BS0N.

IRIDESGBNT SURFACE.

No. 551,769. f Patented Dec. 24, 1895.

9,3/ nvenr,

UNITED STATES PATENT OEETCEe i JOHN JACOBSON, OF BOSTON, MASSACHUSETTS.

IRIDEscl-:NT SURF-Aca SPECIFICATION forming part of Letters Patent No. 551,769, dated December 24, 1895.

.Application led March I5, 1893. Serial No. 466,040. (No specimens.)

To all whom it may concern: Y

Beit known that I, J oHNJ AcoBsoN, of Boston, county of Suffolk, State of-Massachusetts, have invented an Improvement in Iridescent-Surfaced Articles, of which the following description, in connection With the accompanying drawings, is a specification.

My invention consists in an article having its surface provided With striations composed of the successive convolutions of a continuous line upon said surface whichr is therebyl rendered iridescent,the articles thus being4 ornamental and adapted for use as buttons or other articles which may be made more ornamental by having a surface that is iridescent or capable of decomposing the light rel flected from it.

It is Well known that the iridescence or decomposition of light produced by mother-ofpearl, for example, is caused by minute stria` necessary to rule or engrave the surface with great care by special appliances. Such lines have heretofore been produced upon fiat surfaces by a tool or graver having a reciprocating rectilinear movement with relation to the surface, or a corresponding movement of the article under the graver, there being aininute lateral feed of the graver between its successive cutting operations. Such operation is necessarily y slow and attended with many diiiiculties, rendering the production of surfaces in this manner very slow and costly, as before stated.

The present invention is based'on the discovery that a striated light-dispersing surface may be produced by ruling a continuous spiral line the successive convolutions of which are substantially parallel With one another and very close together and uniformly spaced, and thus cause the desired dispersion of the light falling upon the said surface to give the same an iridescent appearance. Such a line may be produced upon an article having a cylindrical surface by rotating the latterv While the tool or graver is pressed against it and feeding the tool in line with the axis of the cylinder in proportion to its rotary movement, so that the part at any time being marked by the tool is adjacent to the niarkv made at the preceding rotation of the article and the continuous tool-mark does not differ substantially in light-dispersing effect from aseries of separate tool-marks or lines each extending continuously around the surface ina plane at right angles to the axis thereof.

A similar striated surface may be produced upon a cone by rotating the latter and feeding the tool along the slantheight of the same, or it may be produced upon a fiat-surfaced article by' rotating the same so that the successive convolutions of the line engraved by the tool are substantially the same in lightdispersing effect.

Figure 1 is a side elevation of acylindrical article having a striated or light-dispersing surface embodying this invention, and Fig. 2 a representation of a flat-surfaced article provided With light-dispersing striations in accordance with this invention.

The article forming the subject of this invention is provided with a continuous line ruled or engraved upon its surface the successive convolutions of which are equidistant from one another and'very close together, so that the said successive convolutions of the continuous line do not differ substantially from separate parallel lines, and aiford a light-dispersing or iridescent surface. Such a continuous line may be ruled upon the surface of a cylinder in the form of a helix or cylindrical spiral, as indicated in Fig. l, or upon a flat surface in the form of a fiat spiral, as indicated in Fig. 2, the lines in both iigures being greatly exaggerated, as in practice they are so minute and the successive convolutions so close together that it would beimpossible to represent them in ther actual size by a mechanical drawing. ln practice the lines will be so ruled as to produce anywhere from about seven or eight hundred up to several thousand striations to the inch. A continuous spiral line of this kind can be ruled roo' ` or striated .by the directaction of the graver;

or, if desired, an article having its surface striated by engraving a continuous line thereon, as herein described, may be employed as a die to transmit the counterpart of its sur` face to other articles, in which case the Striations of a cylindrical surface such as represented in Fig. 1 may be imparted to a fiat or plane surface.

It may be possible in some cases to rule two or more lines simultaneously by employing two or more graVing-tools, the line produced by each tool being in the form of a spiral, the several eonvolutions of which are substantially pa 'allel and equidistant, and an article having the irdesccut surface resulting 4therefrom would be within this invention.

I claim- An irideseent surfaced article having its surface provided with a continuous spiral line the successive convolutions of which are equi-distant from one another and suiicicntl y close together to produce dispersion of light, substantially :is described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

JOHN JACOBSON.

Witnesses:

Jos. P. LIVERMORE. M. E. HILL. 

